Alphanumeric keyboards used in typewriters, computers, and in certain scientific instruments are most often arranged such that the front edge of the keyboard surface is lower than the rear edge of the keyboard surface. Accordingly, a keyboard operator must elevate the hands with respect to the forearms in order to strike the keys. The medical community has become aware of an affliction known as “carpal tunnel syndrome” which effects the median nerve extending down the arm and out to the hand. This median nerve can be exacerbated by repetitive keyboard operation wherein the hands are elevated in comparison to the forearms.
In order to overcome this undesirable affliction, it is known to provide a keyboard support at a reverse angle or inclination such that the hand and fingers are allowed to droop normally at a level parallel with or somewhat below the forearms. Performing keyboard operations while the hands are in this position can help to prevent carpal tunnel syndrome. One example of a prior art reference which discloses such a reverse angled keyboard support apparatus includes U.S. Pat. No. 5,567,067. This invention discloses a keyboard positioning system in which the keyboard is positioned with its rear edge substantially lower than its forward or operator edge in order that the operator uses the keyboard with the plane of the operator's hands parallel to, or below the line of the operator's forearm, this reducing the incidence of carpal tunnel syndrome. A hand support bar is provided to support the operator's hands while keyboarding.
Another example of a keyboard support device utilizing a reverse inclination is that shown in U.S. Pat. No. 5,833,378. This reference discloses a keyboard support tray having folding legs. The legs have risers to enable adjustment of a support deck to a height so that a hinged tray depends at an approximate negative angle of 25°. The support deck has a height to support a wrist pad at just below the user's wrists to enable typing with a 0° angle from the wrist to the forearm.
Our earlier U.S. Pat. No. 6,543,949 discloses a keyboard support apparatus to help prevent afflictions such as carpal tunnel syndrome. The structure of this apparatus is characterized by a foldable support having a base panel, an incline panel, and means for adjusting the incline of the incline panel with respect to the base panel. The inclined panel is rotatably connected to the base panel, and a user may selectively adjust the inclination of the incline panel to best support the user's arms and wrists thereby placing the hands in a more natural position.
While each of the aforementioned inventions may help to overcome carpal tunnel syndrome or other afflictions, there is still a need for a support apparatus that is of simple construction, and allows a user to adjust the angle at which the hands are positioned for keyboarding operations to optimize a natural position to prevent such afflictions.